Chapter 2.1 Flashcards
Is there an infinite amount of water in the biosphere?
No, there is a limited amount but it is recycled naturally
What is transpired?
When water is lost to the atmosphere through the pores of a plants leaves called stomata
What is evapotranspiration?
The combined evaporation and transpiration from a terrestrial area
What process is water a product of?
Cellular respiration
What results in the production of water during cellular respiration?
The breakdown of glucose
What makes up the metabolism?
All the chemical reaction that occur within an organism
What is the water produced in cellular respiration called?
Metabolic water
Where are the hydrogen and oxygen atoms that make up metabolic water found?
Glucose and atmospheric oxygen gas
What is the biogeochemical cycles?
The route that water and other chemical nutrients take through the biotic and abiotic components of the biosphere
What percentage of water in the biosphere exists as liquid form and why?
97% This is due to waters very high boiling point
Where does the water that is found in gas form in the atmosphere come from?
Evaporation and evapotranspiration. Mostly from the oceans
Why is water vapor considered a greenhouse gas?
It traps and transfers heat in the atmosphere
How does water transfer heat to the poles?
Radiant energy from the sun heats water from oceans and evaporates it. As the vapor rises towards the poles it releases heat as it cools
How is heat transferred by liquid water?
Ocean currents transfer warm water to colder parts. The warm water can heat the air causing a change in temperature
What properties make water an excellent carrier of dissolved minerals?
- Water is a universal solvent
- Water has a relatively high boiling and melting point
- Water has special adhesive and cohesive properties
- Water has a high heat capacity
What does a water molecule consist of?
Two hydrogen atoms that are covalently bonded to one oxygen atom
What is the charge of the hydrogen end of a water molecule? Oxygen end?
Slightly positive
Slightly Negative
What do the charges on water molecules make it?
Polar
What kind of bond does the polarity of a water molecule allow it to make?
Hydrogen bonds
What is a hydrogen bond?
A weak attraction between the hydrogen of one molecule and oxygen of a nearby molecule
What does the structure of water enable it to do?
Enables it dissolve a wide variety of substances (ionic and molecular)
What does hydrogen bonding explain?
Why water remains liquid over a large temperature range and why water can continue to dissolve and transport substances over a large temperature range
Why do hydrogen bonds form, break free, and re bond regularly?
Because individual hydrogen bonds are relatively weak
Why is a large amount of energy needed to break many bonds in water?
Because many hydrogen bonds together are strong
Why does ice float on water?
Because when the hydrogen bonds freeze they expand into a crystalline structure making the ice less dense than the water causing it to float
What happens when ice melts?
The crystal structure begins to break down and the loosened molecules pack more closely together and fill in spaces in the collapsing sold structure (increasing density)
What is the highest density of water?
1 kg/L at 4° C
What happens when water falls into spaces between rocks and soil and freezes?
It expands and unlocks nutrients
How does ice provide refuge for aquatic life?
The ice on top insulated aquatic life
What is Cohesion?
The attraction of water molecules to each other created by hydrogen bonding
What is responsible for surface tension?
Cohesion
What is Adhesion?
The attraction of water molecules to other substances
What kind of forces does adhesion provide?
An upward force with water and counteracts the forces of gravity
What explains transpiration in plants?
Cohesion and adhesion
What is heat capacity?
A measure of the amount of heat a substance can absorb or release for a given change in temperature
How is energy and changes in temperature related in water
Substances with high heat capacities require large amounts of energy to create temperature change.
Which is why water heats up slowly and holds temperature longer
How does the property of the ability to hold large amounts of heat aid organisms?
Organisms with a lot of water in their tissues can maintain high temperature because of this property in water
How do organisms gain water?
Eating, drinking and absorbing water through their skin. Also through cellular respiration
How do organisms lose water?
Through breathing and sweating and urine and feces
What are the 2 largest natural disasters in Canada?
Droughts in the prairie provinces
Why is water quality an issue?
Water cannot be considered useful if it cannot cleaned of chemicals
What happens when water is scarce?
Plants close their stomata to stop transpiration but this also stops photosynthetic activity. because of no carb dioxide
What happens to trees when there is a drought?
Their roots dig deeper to access water
